<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>回调函数</title>
</head>
<body>
    
</body>
<script>
    var add=(a,b)=>a+b
    function sum(add){
        return add
    }
    console.log(sum(add(1,2)))
</script>
</html>